2So THE MAMUS. [chap. 



phalanx is enormously developed, larger in the diird dian 

 in the fourth and fifth digits. 



A still further modification of the same type is seen in 

 the extraordinary manus of the great Armadillo (Friodon- 

 tes gigas)^ the largest existing member of the group (Fig. 

 102). The metacarpals of the three outer toes are still 

 further reduced in length, the ungual phalanx of the third 

 is increased in size, while that of the fourth, and especially 

 the fifth, are greatly diminished. 



In the genus Tolypeutes, the manus is formed on a some- 

 what similar type ; but in the Nine-banded Armadillos 

 (genus Tatusia) it is altogether different, the second and 

 third toes being subequal (the third the longest), with mode- 

 rate, conical, and slightly compressed ungual phalanges : and 

 the first and fourth also nearly equal and smaller, all with 

 the normal number of phalanges. The fifth is absent, or 

 (as in T. hybrida) represented by three very rudimentary 

 nodular bones. 



Order Marsupialia. — The carpus never has a distinct 

 OS centrale. It is commonly stated that there is a scapho- 

 lunar bone ; but the lunar, though always .small, is distinct 

 in Didelphys, Pera?neles, Dasyiwus^ Thylaciniis, Phalangista, 

 and Hypsiprymmis (where it is very minute) ; and its ab- 

 sence in Maa-opiis appears to be due rather to suppression 

 than to coalescence with the scaphoid. In Phascolomys a 

 small lunar is present in some individuals, and not in 

 others. 



With the exception of the genus CJmropus^ all known 

 Marsupials possess the normal number of digits and pha- 

 langes, and the manus is short and rather broad, with 

 moderately developed, compressed, curved, ungual pha- 

 langes. 



The little "pig-footed " insectivorous Marsupial Choiropus 



